The invention discloses a novel automatic medicinal liquid mixing device, which comprises a shell and a hydraulic cylinder. According to the novel automatic medicinal liquid mixing device, by arranging a clamping device, an injector can be fixed to the clamping device, and operation is convenient; by arranging the hydraulic cylinder, a movable plate can be driven to move up and down, and the function that a needle of the injector is automatically inserted into a saline bottle is achieved; a pressing rod is arranged, and a first motor drives a circular plate to rotate, so that the pressing rodpresses an injection handle of the injector, medicinal liquid in the injector is automatically mixed into saline, and the working efficiency is high; by arranging a stop block, the pressing rod can bepushed to retract, preparation is made for the next time of injection, and the operation efficiency is high; by arranging a mixing device body, the saline bottle fixed to the mixing device body can be driven to rotate, so that the saline and the medicinal liquid are mixed fully and evenly, and the working efficiency is high; and the novel automatic medicinal liquid mixing device is convenient tooperate and simple in structure and has the advantages of high operation efficiency and even mixing.